Vehicular doors typically include an internal structure or frame, which is covered on an exterior side by an exterior body panel, and is covered on an interior side by an interior trim panel. The internal structure of the door typically includes a beltline reinforcement member, which extends along the beltline of the vehicle. The term “beltline” refers to a line extending rearward from a hood of the vehicle, and usually follows a bottom edge of the side windows of the vehicle. The beltline reinforcement member provides stability and strength to the internal structure of the door, and supports the exterior body panel and the interior trim panel along the beltline. Typically, the beltline reinforcement member is comprised of several independently formed or stamped metal components that are then attached together, such as by welding or with fasteners, either directly or indirectly via other components of the door.